Endovascular catheters are commonly used to permit internal treatment of patients suffering from vascular disorders. For example, catheters may be used for angioplasty, and may be used to deliver embolic devices useful in occluding blood flow through a patient's vasculature. Blood flow occlusion may be useful in controlling vascular bleeding, controlling blood supply to tumors, and to occlude vascular aneurysms, including intracranial aneurysms. When treating blood vessels of extremely small size, for example, intracranial blood vessels, microcatheters may be employed.
Cerebral aneurysms and other vascular defects may sometimes be treated by delivering one or more embolic members (e.g., small coils) through a microcatheter positioned at, or near, the aneurysm or vascular defect. The embolic members are typically attached to an elongate deployment apparatus that is advanceable out of the distal end of the microcatheter and then releases the embolic member(s) into or near the aneurysm or vascular defect. The deployment apparatus is typically flexible enough to be advanced through blood vessels with minimal trauma to the damage to the blood vessels. To improve the advancement of the deployment apparatus, and to protect the deployment apparatus and the accompanying embolization member(s), the deployment apparatus and the accompanying embolization member(s) may be initially positioned within the lumen of a more rigid sheath. Such sheath is typically removed and discarded as the deployment apparatus and the accompanying embolization member(s) are advanced into the microcatheter. The sheath is flexible enough to permit the deployment apparatus to bend and follow the path of the microcatheter, yet is rigid enough to provide structural support so that the deployment apparatus does not inadvertently kink or otherwise become damaged.
In performing endovascular embolization procedures, it may be required to partially or fully withdraw the deployment apparatus from the microcatheter after the sheath has been removed and discarded. For example, if the deployment apparatus feels stressed or is otherwise not positioned properly, it may be desirable to withdraw and reposition the deployment apparatus and the accompanying embolization member(s). However, if the sheath has already been removed from the deployment apparatus in order to permit the deployment apparatus to be inserted into the microcatheter, it is typically necessary to discard the entire deployment apparatus and accompanying embolization member(s) and to replace them with a new deployment apparatus and the accompanying embolization member(s) housed within a new protective sheath. The discarding of a useable deployment apparatus and the accompanying embolization member(s) simply because they cannot be re-inserted into their protective sheath constitutes a significant waste of money and resources. In addition, typical vascular embolization procedures require extreme skill and time, and having to completely remove and reinsert a new deployment structure into a microcatheter results in a significant waste of time, which may negatively affect patient outcome.
Thus, there remains a need in the art for the development of new embolization systems wherein the deployment apparatus and the accompanying embolization member(s) may be resheathed, thereby enabling the deployment apparatus and the accompanying embolization member(s) to be reinserted and repositioned during the performance of a transluminal embolization procedure.